package leetcode.l0603;

import java.util.*;

/**
 * @author Retain
 * @date 2021/6/3 17:33
 */
public class Medium_电话号码的字母组合_17 {

    // todo:待补充回溯排列组合
    Map<Character,List<Character>> map = new HashMap<>();
    public List<String> letterCombinations(String digits) {
        initData();
        ArrayList<Character> list= new ArrayList<>();
        for (int i = 0; i < digits.length(); i++) {
            list.addAll(map.get(digits.charAt(i)));
        }
        return null;
    }

    private void initData() {
        map.put('2', Arrays.asList('a','b','c'));
        map.put('3', Arrays.asList('d','e','f'));
        map.put('4', Arrays.asList('g','h','i'));
        map.put('5', Arrays.asList('j','k','l'));
        map.put('6', Arrays.asList('m','n','o'));
        map.put('7', Arrays.asList('p','q','r','s'));
        map.put('8', Arrays.asList('t','u','v'));
        map.put('9', Arrays.asList('w','x','y','z'));
    }

    static class TreeNode{
        TreeNode left;
        TreeNode right;
        int val;
        public TreeNode(int val) {
            this.val = val;
        }
    }
}
